• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.61.4-62
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• 2017

In this study we have made a statistical investigation on the kinematic classification of coronal mass ejections (CMEs) using about 4,000 SOHO/LASCO CMEs from 1996 to 2015. For this we use their SOHO/LASCO C3 data and exclude all poor events. Using the constant acceleration model, we classify these CMEs into three groups: Acceleration group, Constant Velocity group, and Deceleration group. For classification we adopt four different methods: Acceleration method, Velocity Variation method, Height Contribution method, and Visual Inspection method. Our major results are as follows. First, the fractions of three groups depend on the method used. Second, the results of the Height Contribution method are most consistent with those of the Visual Inspection method, which is thought to be most promising. Third, the fractions of different kinematic groups for the Height contribution method are: Acceleration (35%), Constant speed (47%), and Deceleration (18%). Fourth, the fraction strongly depend on CME speed; the fraction of Acceleration decreases from 0.6 to 0.05 with CME speed; the fraction of Constant increases from 0.3 to 0.7; the fraction of Deceleration increases from 0.1 to 0.3. Finally we present dozens of CMEs with non-constant accelerations. It is found that about 40 % of these CMEs show quasi-periodic oscillations.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1699-1703
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• 2012

Cervical cancer remains the most frequent cancer in women from the developing world. More than 88% of deaths occur in low-income countries, and it is predicted to climb to 91.5% by 2030. Although Pap-based screening programmes have shown to be effective in reducing the disease burden in high-resource countries, implementation and sustention of cytology-based programmes is quite challenging in low-resource settings. The present paper reviews evidence-based alternatives of screening methods, triaging algorithm, treatment of cervical precancerous lesions, and age-group at screening appropriate for low-income countries. Evidence shows that visual inspection methods using diluted acid acetic or Lugol's iodine, and HPV-DNA testing are more sensitive tests than the Pap-smear screening test. Visual inspection allows an immediate result and, when appropriate, may be immediately followed by cryotherapy, the so called "screen-and-treat" approach, achieved in a single visit, by trained nurses and midwives. Examples of cervical cancer prevention programmes in India and selected low-income countries are given.

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.43-50
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• 1999

The safety-evaluation of ancient wood structures has been executed with only visual inspection. The application of NDE(nondestructive evaluation) is required because the visual inspection has many restrictions. Among many NDE techniques, the stress wave technique was used in this research. This study focused on evaluating the extent of decay in members of ancient structures, using stress wave nondestructive technique. For application of stress wave technique to ancient structures, the threshold time which divides members into categories according to degree of decay should be determined in advance. Stress wave timer (Metriguard Model 239A) was used in this study, specimens used in this research were the members obtained from six ancient structures. All specimens were identified as Hard Pine(Pinus densiflora S. et Z. or Pinus thunbergii P.) by microscope. Each member was tested with stress wave passing radially through the pith. In this study, the stress wave time of $12{\mu}s$/cm could distinguish between sound and decayed specimens with accuracy of 77.5 percent. Also, decayed specimens could be separated into moderate and severe categories by stress wave time of $20{\mu}s$/cm. Among the three decay location groups (exterior, mixed, interior), the exterior group could be classified into sound, moderate and severe decay with the greatest accuracy. Stress wave transit time was not sensitive to small decay pockets located in interior of the member.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.2
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• pp.107-111
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• 2016

This paper presents electrochemical corrosion behaviors of cement mortar specimens in the high salinity condition. Chloride ion is known as the most detrimental parameter to cause the corrosion in reinforced concrete. Increasing the concrete cover thickness is one of the corrosion protection methods against chloride ion; so, this study mainly focuses on the effects of mortar cover thickness on corrosion protection. In specimens, rebar, which was a height of 200 mm and a diameter of 10 mm, was installed at the center of the small size form. Later on, mortar was injected into the form, and 10, 20, 30, 40, and 50 mm of the different mortar cover thicknesses were selected. Potential measurements, linear polarization resistance tests, and cyclic potentiodynamic polarization tests were performed for specimens that were exposed to seawater. These results were compared with visual inspection results of rebar. The results show that an increase in the cover thickness contributes to corrosion protection. In addition, the result of electrochemical corrosion tests generally agreed with that of an autopsy visual inspection.

• Journal of Powder Materials
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• v.13 no.2 s.55
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• pp.138-143
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• 2006

In this study, the effects of the dispersants, i.e., Hypermer KD-2 and poly(l-vinyl-2-pyrrolidone) (PVP), and their concentration on the dispersion stability of Ni nanoparticles ($10nm{\sim}40nm$) in ethanol were investigated by using a visual inspection, a transmission profile (Turbiscan), and a zeta potential measurement. The transmission profiles measured by Turbiscan showed that the particle size increased over the entire height of the sample for suspensions with both the dispersants without showing any particle coalescence and sedimentation. The visual inspection also confirmed that the Ni suspensions with Hypermer KD-2 and PVP were very stable for more than a year. The zeta potential values varied from positive to negative with increasing the dispersant's concentration. The dispersion stability of the suspensions was not affected by both the dispersant's concentration and the zeta potential values. The observed suspension stability of Ni nanoparticles was attributed to the steric effect for the Hypermer KD-2 and to the bridging effect for the PVP.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.55-64
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• 2008

Shotcrete have become a deterioration which was exposed to harmful environments. In this study, in order to evaluate the deterioration properties of shotcrete, visual examination, compressive strength, adhesive strength, microstructural analysis were investigated up to the 60th weeks of exposure. The attack solutions for test are sodium sulfate and hydrochloric acid solution with different concentrations, respectively. From the results, although the compressive strength of shotcrete specimens and the adhesive strength between specimens and rocks were high at the early immersion age, they rapidly dropped in the subsequent phases, especially in 5% sodium sulfate and pH1 hydrochloric acid solution. With continued exposure, various harmful ions penetrated into the shotcrete specimen, reacted with the cement hydrate, and generated expansion substances. It was verified that the shotcrete specimens suffered a serious deterioration by chemical attack.

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.129-132
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• 2005

It is one of the most important issues to determine a target brain image that gives a common coordinate system for a constructing population-based brain atlas. The purpose of this study is to provide a simple and reliable procedure that determines the target brain image among the group based on the inherent structural information of three-dimensional magnetic resonance (MR) images. It uses only 11 lines defined automatically as a feature vector representing structural variations based on the Talairach coordinate system. Average characteristic vector of the group and the difference vectors of each one from the average vector were obtained. Finally, the individual data that had the minimum difference vector was determined as the target. We determined the target brain image by both our algorithm and conventional visual inspection for 20 healthy young volunteers. Eighteen fiducial points were marked independently for each data to evaluate the similarity. Target brain image obtained by our algorithm showed the best result, and the visual inspection determined the second one. We concluded that our method could be used to determine an appropriate target brain image in constructing brain atlases such as disease-specific ones.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.5
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• pp.439-448
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• 2022

MV (Moving Vehicle) detection using satellite imagery is important for traffic monitoring and provides a wide range of observations. Specifically, MV detection methods utilizing the time lag in single-pass optical satellite images have been studied for detecting MVs from a single set of images. Because of limitations in detecting MVs outside of roads, most previous studies required road information to limit the moving object to cars on the road. However, it is difficult to obtain road information from inaccessible areas. Therefore, this study proposed a new method for detecting MVs regardless of their locations from single-pass optical satellite images without using additional data. WV-3 (Worldview-3) satellite images were used, and a spatial correlation coefficient map was proposed to detect spatial displacement which denotes MVs across two WV-3 MS images. Finally, evaluation was performed through quantitative metrics and visual inspection. The evaluation results revealed that the proposed method can detect MV movements from the single-pass satellite images. On the contrary, misdetected or undetected MVs due to radiometric differences between the images could be identified by visual inspection. The performance of the proposed method can be improved by minimizing radiometric variations and adding conditions that are robust to radiometric differences between the images.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.38.3-38.3
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• 2019

We present newly discovered dwarf galaxy candidates in deep wide-field images of NGC 1291 obtained with KMTNet. We identify 15 dwarf galaxy candidates by visual inspection within the virial radius of NGC 1291. Using imaging simulations, we demonstrate that our imaging data is complete up to 26 mag arcsec^-2 or -10 abs.mag with > 70% of the completeness rate. We also apply automated detection method to find the dwarfs. However, the completeness and the reliability are relatively low compared to the visual inspection. We find that structural and photometric properties of dwarf candidates such as effective radius, central surface brightness, Sérsic index, and absolute magnitude appear to be consistent with those of known dwarf galaxies in nearby groups and clusters, except for color. NGC 1291, residing in a relatively isolated environment, tends to accompany bluer dwarf galaxies (≃0.58) than those in denser environment. It shows that the quenching of dwarfs is susceptible to the environment.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.5
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• pp.520-525
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• 2003

Fast Breeder Test Reactor (FBTR) is a 40MW (thermal) / 13.2MW (electrical), Plutonium - Uranium mixed carbide fuelled, sodium cooled, loop type nuclear reactor operating at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam. Its main aim is to generate experience in operation of fast reactors and sodium systems and to serve as an irradiation facility for development of fuels and structural materials fur fast reactors. Nuclear reactors pose difficulties to the NDT techniques used to monitor the conditions of the internal components. Sodium cooled fast breeder reactors have their own typical difficulties in using the NDT techniques. These are due to the need for operation in aggressive environment of nuclear radiation and sodium (molten/vapour), as well as the need to maintain leak tightness of a very high order during all states of reactor operation and shutdown for fuel handling, maintenance and remote inspection. This paper discusses the following NDT techniques, which have been successfully used for the past 15 years in FBTR: (i) Periscope and Projector, (ii) Core Co-ordinate Measuring Device and, (iii) Optical fiberscope. The inspection using these techniques have given confidence for further reactor operation at high power by giving useful data on the conditions of the components inside the reactor vessel.